iOS Swift - Singleton data persistance

I am developping an application that saves informations about the logged-in user in CoreData and singleton class. After the user log-in, I'm fetching data from coredata and set the variables from the singleton.

My question:

If the app receives memory warning issue, and the data from the singleton will be released, my app will crash. What can I do in this situation?

Let's say you have a local property named NSArray *myArray in singleton's .m file where you store all the needed data. All you need to do is to add a method in header file which returns that array if is not nil, and in case of nil make it reload from storage and return.
Also override - (void)didReceiveMemoryWarning method and save the data in case of memory warning.
Here is a sample code written in objective-c: